1. Field of the Invention
This invention relates to a battery pack charging device for charging a battery pack accommodated in e.g., portable electronic equipment to supply DC power thereto.
2. Description of Related Art
A battery pack charging device charges a battery pack, comprised of for example a lithium ion secondary cell, sealed in a casing, with the battery pack being loaded in a battery loading section of the charging device. In general, the battery pack charging device includes a DC power supply circuit, a current detection circuit or a control circuit, enclosed in a housing, and also includes, in the battery loading section, a charging terminal unit for connection to a charging terminal of the battery pack, and a communication terminal for exchanging the information with the battery pack. The battery loading section of the battery pack charging device is provided with a detection switch for detecting the loading of the battery pack.
When the loading of the battery pack into the battery loading section has been confirmed by a detection switch, the DC current is supplied from a DC power supply to the charging terminal for charging the battery pack.
Meanwhile, in the battery pack charging device, the respective terminals of the charging terminal unit provided in the battery pack are reduced in pitch, in keeping with reduction in size and thickness of electronic equipment, as a consequence of which the terminals of the charging terminal unit are also reduced in pitch. In the battery pack charging device, the detection switch has to detect the battery pack of preset design parameters, loaded in the battery loading section, to high precision, and hence the detection switch is provided in the battery loading section as the detection switch is positioned to high accuracy relative to the charging terminal unit.
On the other hand the battery loading section of the battery pack charging device is of varied structures in order to cope with varied design parameters for voltage, charging or outer shapes of the battery packs used for a wide variety of electronic equipment. The conventional battery pack charging device has a drawback in that, since the charging terminal unit and the detection switch are assembled in the battery charging sections in a state in which the charging terminal unit and the detection switch are assembled in position relative to one another, the structure is complicated, while the number of assembling steps is increase to render it difficult to maintain the assembling accuracy. In the battery pack charging device, the charging terminal unit and the detection switch may be of a unified structure and arranged in this state in the battery loading section to assure high precision relative positioning.
However, since the battery pack charging device is constructed to meet widely diversified battery packs, the unit comprised of a unified structure of the charging terminal unit and the detection switch has to be changed for each new version of the battery pack. The unit comprised of the unified structure of the charging terminal unit and the detection switch, formed by a metal die device from e.g., a synthetic resin material, needs to be of high precision and hence is expensive, thus excessively raising the cost of the battery pack charging device. In particular, in the battery pack charging device, the battery pack may be introduced into the battery loading section at for example 90xc2x0 different positions, such as in the vertical direction and in the horizontal direction. In such case, totally different units must be prepared for these two inserting directions, thus not only raising the cost but also protracting the term of production.
It is therefore an object of the present invention to provide a battery pack charging device including a terminal structure which, even if the battery pack is loaded in a different loading direction, may be adaptively used to enable the charging of the battery pack and reliable loading detection to reduce the cost.
For accomplishing the above object, the present invention provides a charging device for charging a battery pack including a charging terminal member arranged in a loading section in which the battery pack is accommodated, the charging terminal member being connected to a charging terminal of the battery pack, and a detection switch including an actuation member actuated by the battery pack and a switching element opened/closed by the actuation member, the detection switch serving for detecting the loading of the battery pack. A first battery pack and a second battery pack, having different loading directions, are introduced into the loading section of the battery pack loading device. A charging terminal member and a detection switch are loaded on a terminal block member of synthetic resin mounted in the loading section of the battery pack charging device. The battery pack charging device is assembled in such a manner that the charging terminal member can be connected to charging terminals of the first and second battery packs, while the actuation member of the detection switch can be actuated in the same direction by the first and second battery packs.
In the battery pack loading device, the actuation member is slidably assembled to a slide guide unit provided to the terminal block member, and a slide guide projection and a slide guide recess are provided to the outer lateral surface of the actuation member and to the inner surface of the slide guide recess, respectively. In the battery pack charging device, the actuation member is provided with an actuation part protruded into the loading section so as to be thrust by the battery pack. This actuation part is made up by an inclined cam thrust by the first battery pack and a vertically extending cam thrust by the second battery pack.
With the present battery pack charging device, according to the present invention, the terminal block member, carrying the charging terminal unit and the detection switch for detecting the loading of the battery pack, is adaptively used for the loading section for loading the battery pack in substantially the horizontal direction and for the loading section for loading the battery pack in substantially the vertical direction. Thus, with the present battery pack charging device, it is possible to reduce the cost by making common use of a metal die for molding the terminal block member, which is narrow in manufacturing tolerance and expensive. Moreover, with the present battery pack charging device, the detection switch is able to detect the battery pack loaded in different loading directions, with the charging terminal section being connected to the charging terminal of the battery pack to effect charging. Additionally, with the present battery pack charging device, the detection switch and the charging terminal unit may be positioned relative to each other on loading thereof to the terminal block member to assure reliable battery pack loading detection and charging.